Most of the island comprises of subtropical evergreen forest dominated by broadleaved species; however, with a rise in elevation, this forest type is gradually replaced by conifers and deciduous hardwoods. Taiwan has a tropical monsoon climate with a mean annual temperature of 22۫ C and a precipitation pattern which varies throughout the length of island. In general, the eastern slopes of the island receive the most rain, up to 6000 mm annually; while the western plains receive only about 1500 mm. Taiwan is subject to intense typhoons, especially on the eastern seaboard. Most of the island's 26 conifers species occur at elevations of 2000 m and above. Currently sixteen species are threatened mainly as a result of forest clearance for commercial plantations and agriculture